Moratti is keen to keep the pressure on his players after Friday's disastrous 3-1 defeat to Lazio in Serie A.
He said: “It's obligatory to do well because you just can't make bad impressions in the Champions League. Then we'll see what has significance after the Club World Cup.
“The feeling is that we need to do well. Psychologically we hope to do well against Bremen in the last game remaining before the Club World Cup.”